The Pd(100)-(SQRT(5) x SQRT(5) R27^o)-O surface oxide revisited

TL;DR

This study reexamines the structure of a specific PdO surface oxide, using advanced spectroscopy, microscopy, and computational methods, and proposes a new model that aligns better with experimental data than previous models.

Contribution

It introduces a revised structural model of the Pd(100)-(SQRT(5) x SQRT(5) R27^o)-O surface oxide based on combined experimental and theoretical analysis.

Findings

Previous PdO(001) film model is incompatible with all methods.

Proposed model is a strained PdO(101) layer on Pd(100).

LEED calculations support the new structural model.

Abstract

Combining high-resolution core-level spectroscopy (HRCLS), scanning tunneling microscopy (STM) and density-functional theory (DFT) calculations we reanalyze the Pd(100)-(SQRT(5) x SQRT(5) R27^o)-O surface oxide phase. We find that the prevalent structural model, a rumpled PdO(001) film suggested by previous low energy electron diffraction (LEED) work (M. Saidy et al., Surf. Sci. 494, L799 (2001)), is incompatible with all three employed methods. Instead, we suggest the two-dimensional film to consist of a strained PdO(101) layer on top of Pd(100). LEED intensity calculations show that this model is compatible with the experimental data of Saidy et al.